do
 {
 printf("1. insert element at first position \n");
 printf("2. insert element at last position \n");
 printf("3. insert element at position by user \n");
 printf("4. display array \n");
 scanf("%d",&ch);
 switch(ch)
 {
  case 1 : first(a);
    break;
  case 2  : last(a);
    break;
  case 3 : pos(a);
    break;
  case 4 : display(a);
    break;
  default : printf("invalid choice \n");
    break;
 }
 printf("do you want to continue(1/0) \n");
 scanf("%d",&i);
 }while(i==1);
}
void first(int a[])
{
 int i;
 printf("enter value \n");
        scanf("%d",&i);
        a[0]=i;
}
void last(int a[])
{
 int i;
 printf("enter value \n");
        scanf("%d",&i);
        a[4]=i;
}
void pos(int a[])
{
 int i,n;
  printf("enter position to insert \n");
         scanf("%d",&n);
         if(n>5)
          printf("invalid position \n");
         else
         {
          printf("enter value \n");
                 scanf("%d",&i);
                 a[n-1]=i;
          }

}
void display(int a[])
{
 int i;
 for(i=0;i<5;i++)
 {
  printf("%d \t",a[i]);
 }
}